1. You can trust a negative result 19 days after the sex in question. 2. Maybe, however it's more likely that you skipped your withdrawal bleed as a side-effect of HBC itself. Some brands are notorious for very light or missing bleeds. Loestrin is one, and Microgestin is a generic for it. A single missed bleed is generally not cause for alarm. 3. There are only a couple of antibiotics that have been proven to affect HBC, in the Rifampicin family. These are hardcore abx used to treat things like tuberculosis. You do NOT need backup for most normal antibiotics (like Flagyl). However, IF your protection was compromised, seven days of active pills will get you protected again.
no subject
2. Maybe, however it's more likely that you skipped your withdrawal bleed as a side-effect of HBC itself. Some brands are notorious for very light or missing bleeds. Loestrin is one, and Microgestin is a generic for it. A single missed bleed is generally not cause for alarm.
3. There are only a couple of antibiotics that have been proven to affect HBC, in the Rifampicin family. These are hardcore abx used to treat things like tuberculosis. You do NOT need backup for most normal antibiotics (like Flagyl). However, IF your protection was compromised, seven days of active pills will get you protected again.